Grinding machine



Jan. 8 1924.

W. TAYLOR GRINDING MACHINE Filed Aug. 9. 1917 "(Sheets-Sheet 1 Jan. 8 1924.

W. TAYLOR GRINDING MACHINE Filed Aug. 9, 1917 '7 Sheets-Sheet 2 Jan. 8 1924.

w. TAYLOR GRINDING MACHINE Filed Aug. 9, 1917 '7 Sheets-Sheet 3 fwenbr [0% 7 1 g;

Jan. 8 1924.

W. TAYLOR GRINDING MACHINE Filed Aug. 9. 1917 "(Sheets-Sheet 4 Jan. 8,1924 1,479,843 W. TAYLOR GRINDING MACHINE Filed Aug. 9, 1917 7 Sheets-Sheet 5 awvewcoz Jan. 8 7 1924 w. TAYLOR GRINDING MACHINE 7 sheets 7 Filed Au 9 1917 Patented Jan. 8, 1924.

UNITEIS STATES PATENT OFFICE.

WILLIAM TAYLOR, OF -LEIGESTEB, ENGLAND.

" GRINDING MACHINE.

Application filed August 9, 1917. Serial No. 18 5388.

is a specification.

This invention relates to machines "for grindmg spherical surfaces by means of abrasive wheels, and especially for grindingthe convex surfaces of lenses when such lenses are made from discs of glass, the machines being of the kind in which the work is mounted and rotated on a .work spindle about a primary axis, and a relative motion of the work nd the abrasive wheel is effected about a secondary axis intersecting the primary axis of the work spindle, th abrasive wheel operating on the Workat a point in the plane which containsthe ,primary axis at all times, and the radius of the spherically curved surface formed being variable by varying the distance in such plane between the operative point of the wheel and the secondary axis. The invention consists in improvements which are hereinafter described and have for their principal objects to provide a machine of the kind above referred to, in which the rotation of the work about its primary axis and the relative movement of the work and abrasive wheel about the secondary axis are effected automatically, and in which the said relative movement may be produced by a predetermined limited force and'can be effected at a varying rate.

I wi 1 describe my invention with the help of the accompanying drawings which illustrate a grinding machine having the improvements applied and arranged to grind convex spherical surfaces, the several parts of the machine hereinafter referred to in describing the invention bein indicated on the drawings by means of re erence letters. Fig. 1 of the drawings is a plan of the machine, the work carrying spindle, rotatable about its own, i. e. the primarv axis, being shown in operative relation to the wheel and capable of being turned about a secondary axis; Figs. 2 and 3 show, .respectlvely, front and side elevationsof the machine and of the upper portion of its pedestal; Fig. 2. is a fragmentary horizontal section taken on the line 2"---2 of Fig. 2; Fig. .4 is a front elevation of the lower portion of the pedestal; Fig. 5 is an elevation at right angles to the view in- Fig. 4, of a part of the pedestal wall shown in that figure; Fig. 6 is a vertical section of the upper part of the 'ma-.

chine and the upper portion of the pedestal on the plane indicated by the lines 6-8 in Figs. 1, 11, 12; Fig. 7 is a, fragmentary side elevation showing the driving mechanism for the work spindle and partly sectioned upon the plane indicated by the lines 77 in Figs. 1, 6; Fig. 8 is a vertical section ofthe lower portion of the pedestal on the plane indicated by the lines 6-8 in Figs. 1, 11,. 12; Fig. .9 is a front elevation of the mechanism within the lower part of the podestal; Fig. 10 is a horizontal section of the parts shown in Fig. 9, on the plane indicated by the lines 1012 of Figs; 4, 8, 9; Fig. 11

is a horizontal section upon the plane indicated by the lines 11+11 in-Fig. 3; Fig. 12 is a horizontal section upon the plane ludicated by the lines 10--12 of Figs. 4, 8, 9; and Figs. 13, 14, 15 are respectively an elevation, plan and end view of a gauge for setting the working face of the abrasive wheel atany required distance relatively to the secondary axis.

In the drawings, A is an abrasive wheel .which maybe of any convenient form, but I prefer that of a cylindrical cup having an annular grinding edge as shown for example in 'Fig. 1. The wheel is mounted upon awheel spindle A, and this is carried in such a manner, as' by means of the screw actuated slide B. that the wheel may be moved toward or from the secondary axis I, to vary the radius of curvature J of the work and to take'up wear of the ,wheel. I supply the wheel witha coolin lubricant througha pipe C, and a pan to catch the surplus liquid and detritus, and discharge the same through outlet D y The wheel may be driven from any convenient source of power by a. pulley A fixed to spindle A The disc E to be ground is chucked on a suitable hollow work spindle F which is rotatably mounted in bushings F,,, F, carried by the tubular portion T of the slide T, the mounting and construction of whlch-are hereinafter explained.

The work spindle F is adapted to receiye a split chuck F of the kind well known in connection with watch machinery and lathes,

the chuck being suitably bored and recessed according to the diameter and thickness of i the glass disc to be held.

mouth of the spindle F so as to gri chuck and has fixed upon it a star wheel F 1n a chamber F of which is a compression "spring F adapted to close the chuck by pulling back the draw-in spindle (Fig. 6). The stren h of this spring is such that while it ho do the glass securely in the chuck F, it does not crush it. In order to secure uniform thickness of the finished work, T may give the work spindle F a limited end shake in its bearings and provide means such as an abutment plunger 1F. carried by the slide T and adapted to take the end thrust of the chuck F through the draw-in spindle F whereby the chuck'may be positioned with respect to the slide T and thus with respect tothe secondary axis independently of the work spindle 15 whose longitudinal position may vary according to the diameter of the blank E.

In order that the spindle may be free endwise for this purpose while beingunable to stray unduly, a retaining collar T is fastened to the spindle F by a screw F and a light compression spring F is provided to thrust against the collar F and a shoulder F on the spindle 15 so as to move the spindle 15 towards the abutment plunger F while a suitable but limited end shake in the bearings is permitted by the space between the collar F and a shoulder F on CJI - the frame T is a post T (Figs. 3, 7) which;

. lllSIn the spindle F (Fig. 6).

The slide T which carries the bearings for the work spindle F is slidably mounted upon a carriage H fixed to the top of a verti 'cal shaft N so that it may be turned about supports the hereinafter described'mechafor rotating the. work spindle T Across the rear end of the frame T is a cover plate T and a saddle piece T in which the abutment plunger F is mounted (Figs. 1, 2, 3). The plunger R, has a shoulder F5 which by engagement with'the saddle piece T prevents the plunger from moving out-- wardly (Fig. 6). The plunger may, howaccuses ever, be pressed inwardly by the chuck opening means hereinafter described. The entire slide T is pressedioutwardly with respect to the carriage H by a compression spring T (Fig. 2). micrometer screw K in a tapped hole in the carriage H and a lever K, pivoted to the carriage H at K, and engaging the plunger T serve to restrain the backward movement of the slide T under the efl'ect of the spring T and may be used for fine adjustment of the position of the slide T in the oarria'e H. The upper portionof the carriage is-split at T1 and a screw bolt H is provided for drawing the carriage together so that it fits ti htly upon the tubular portion T of the slide T and locks the slidein the position to which it me? be adjusted by the micrometer. screw K.

nstead of turning the work about the secondary axis T, I may alternately fix the position of the work and move the abrasive wheel about the seoondaryiaxis. The secondary axisl is referably vertical, and the workspindle an wheel spindle axis preferablylie in one horizontal plane.

The work spindle may be rotated by a belt from any convenient source or power, and in order to rotate the spindle while leaving it free to be moved about the secondary axis, T prefer to drive it by means of worm 01' helical gearing F meshing with a gear F fixed upon the work spindle F (Figs. 6, 7). The worm shaft F is mounted in the pillar T of the slide T with its axis vertical and parallel with the secondary axis ll, and T may drive the worm shaft F by means of a pulley F 5, which may be fixed thereon but is preferably adapted toibe unclutched therefrom automatically at the end of a grinding operation by means hereinafter described, and a driving band passing from a suitable-countershaft over a pair of guide pulleys L, L supported from a pillar D carried by the frame of the machine or pan D, by means of an arm L and a member T 1 pivotally mounted on the arm L and which is connected withthe worm shaft F in such manner that the tension of the band is not varied by the turning of the work about the secondary axis T. The connection between the member L and the shaft F, can be conveniently efiected by means of'a coupling member L and a strut L attached at, one end to the coupling L and at the other end adjustably clamped to member 1L by aid'of the set screw L Means adapted to open the chuck, when a ,finished piece of work is to be replaced by a fresh blank, may be provided and such means or opening device is preferably so placed as to act on the chuck when the work carryin about-"the axls T sufliciently to'attain a pcspindle F has been turned sition wherein the work has become removed comes. unclutched from pulley F as described below. Such a position is hereinafter termed the normal positionof rest,

and may conveniently be that indicated by v draw-in spindle F against the action of a spring F 22 and moves the chuck F out of the tapered mouth of the work spindle F so as to release its grip upon the glass disc E.

I may provide means whereby when the work spindle F is in its position of rest its rotation will cease. To'this end I fix to the pillar D by means of a bracket Gr an. ap-

propriately shaped bar or abutment piece G and I engage the pulley F to the .worm shaft F 9 by means of a clutch pin F fixed crosswise through the shaft and arran ed to engage a notch. F out in the hub u of pulley F,,,. I maintain shaft F, normally in the working or a raised position by means of a spring F supported by a plug F in the bottom of the pillar T for the shaft F While the shaft F is in the raised position the pin F engages the notch F but when the work spindle is turned to its normal position of rest. the fixed abutment piece G thrusts upon the coned upper end F of the worm shaft F and depresses it against the action of spring F so that the pin F is withdrawn from the notch F into a recess F formed in themember L so that the pulley F and shaft F 9 become disconnected and the latter ceases to rotate (Figs. 1,

3 7 Y Bfeans, such as the set of speed pulleys F or worm shaft F may be provided for varying the speed of the work spindle F.

In order to turn the work splndle about the secondary axis I at a suitable speed or speeds and withthe utmost rigidity ,of control, I may 'mount the work spindle car riage H on a vertical shaft N whose axis is the secondary axis, the shaft N being mounted at its upperand lower ends in ball bearings M and Mfand conveniently housed in a pedestalor column 0 which may constitute the machine frame and support thedpan D, and the wheel spindle A, aforesai I preferto effect the turning of the work spindle about the secondary axis by means of asuitably and definitely limited force and to provide means for' limiting the rate of turning so that while it may be less than, it cannot exceed a predetermined rate, and

may vary inversely: with the resistance to grinding. To these ends, upon the shaft N within the coluninI may form a screw N upon which is a nut N and a weight N adapted to move vertically without rotation.

The weight N surrounds, the nut N which is located in a central cylindrical recess in the upper portion of the weight N,. The weight N 3 is retained upon the nut N by a collar N which is screwed to, the top of the Weight N (Figs. 8, 10, 12). The

weight N is retained against rotation by a pin U which is fixed in the wall of the column O The pin U extends through the wall of the column 0 andis prevented from coming out by a cap U which is held to the wall of the column 0 by a screw bolt U, (see Figs. 4, 5, 12). The inner end of the pin U engages a vertical slot N in the weight -N (Figs/5, 9. 12). As the weight N is thus held against rotation it is apparent that when the nut N is locked to the weight N, by mechanism hereinafter described, the descent of the weight N under the force of gravity will'turn the shaft N and the work carried on the upper end .of the shaft about the secondar' axis. Mechanism is provided for raising t 1e weight N, to its starting position after it has descended under the force of gravity. In the form shown in the drawings this mechanism comprises a foot treadle U, connected by a rod 0 to a crank 0 upon a shaft 0 which is journalled in the wall Y of the column 0. The shaft 0 extends both inside and outsideof the wall of the column 0 and the before mentioned crank 0 is atcrank pi-n 0, which extends into a recess N formed in the lower portion ofthe-weight N and serves by engagement with the upper edge N of this recess to raise the weight N when the shaft 0 is rotated by depressing the treadle 0 (Figs. 4, 9. 12).

In order that when the grinding operation is complete'the work may be at once turned backwards about the secondary axis I to its normal position of rest X Y, where the work may be changed, I mount the said nut N rotatably within the weight N and connect it with the weight by locking'means adapted to prevent rotation of the nut within the weight during the grinding operation, and automatic means operating to release the locking means upon the completion of the grinding operation and thus set the shaft N free to be turned backwards by means such as a spring actuated arm P, connecting rod P and crank P provided for the purpose. The locking means shown in the drawings comprise two toggle links N N pivoted together at N The link N is pivoted to the top of the weight N -at N While the link N 5 is pivoted to the top of the nut N at N The links N and N are provided with llti brou ht together when the links are extended (Figs. 9, 10, 12). The mechanism for releasing the locking means or breaking the toggle N,, N, comprises a crank mounted upon the shaft O. The crank may be made integral with the crank O, as shown in the drawings (Figs. 4, 9, 12). The upper end of the crank O, is so located that at the end of a grinding operation it strikes an adjustable screw N in the end N of the toggle link N,.. The spring actuated arm P, the connecting rod P and the crank P, which turn the shaft N backward when the locking toggle is released are best shown in Fig. 11. A dashpot P or equivalent device may be used to prevent too rapid returning of the shaft N. The members P and P may, as shown on the drawing, be parts of an ordinary hydraulic door check.

Cooperating stops Y Y are provided to arrest the backward turning of the shaft N when the axis of the work spindle Freaches XY in Fig. 1.

the position of rest indicated by the line horizontally into the carriage H so that its inner end projects into an arcuate recess H provided in the bottom of the carriage H. he stop Y is fixed. It is formed by the elongation of the head of one of the screws M which secure the cover M, of the ball bearing M tothe upper portion 0,, of the column 0. (Figs. 2, 2 6).

The operation of the mechanism described comprises three steps.

The normal position of the parts of the apparatus,that is, the position which they occupy at the beginning of the first step in the operation and again at the end of the trated in Fig. 10.

while the treadle O, is in. its highest position as indicated in Fig. 4.

third step described.

in the operation will first be The work spindle F is in the position of rest indicated by the line XY in Fig. 1, the shaft N,

which is continually urged to turn in an anti-clockwise direction (looking from the top) by the spring-actuated arm P, being retained against rotation by the en agement of the stop Y, on the the fixed stop Y. The togoccupy the position illus- The weight N is in its carriage with gle levers N N lowest position,

In the first step of the operation the treadle O, is pressed down, pulling down the rod 0 and the crank 0 This rotates the shaft in an anti-clockwise direction (looking from the front of the machine) and raises the crank ()1 from the position shown in Figs. 4 and 9. The pin 0 of the crank O, contacting with the surface N of the weight N raises the weight N while at the same time the crank 0 is moved to the left from the position shown in Figs. 4 and 9. As the weight N is raised, the nut N rotates within the weight N -so that the shaft N is not turned. This rotation of the The. stop Y is screwed amends is in a clockwise direction looking that the pivot point N is oint N, causnut N, from above, so moved away from the pivot ing the toggle links to straig ten out until they occupy the position in cated in Fig.

-12 with their abutment surfaces N in en- N is locked against rotation by tolggle links 11 are in.

N N whose abutment. surfaces engagement with each other, the descent of the weight N and nut N cause the shaft N to rotate. The turning of the shaft N and I the carriage H mounted upon its upper end swings the axis of the work spindle F about the secondary axis ll" from its starting posi-' tion X-Y towards the position of the work spindle F indicated in full lines in Fig. 1. Thisturning of the work axis brings the face of the work progressively into contact with the edge of the grinding wheel A. The descent of the weight N serves also to force down the crank 0., because of the engagement of the crank pin 0 with the surface N of the weight.

0 in a clockwise treadle O and moving the upper end of the crank 0 to the right. When the-grinding operation is completed, which -in the arrangement shown when the center of the disc E has been brought in contact with the edge of the grinding wheel A bgr movement of the axis of the work spindle to the position shown in full lines in Fig. 1, the end of the crank O comes into contact with the end of the screw N in. the portion N, of the link N (Figs. 9, 12). The crank 0 moves the end N, of the link dead center and breaking-the toggle so that the nut N is free to turn within the weight N The third step in the operation begins automatically when the toggle is broken by the end of the crank As soon as the toggle is broken the spring actuated arm P, which has opposed the turning movement of the shaft N under the effect of the weight N during the grinding shaft N backward until the inner end of the stop Y, upon the carriage H engages the fixed stop Y thus swinging the axis of the work spindle F from'the position shown This rotates the shaft direction raising thein the drawing occurs N slightly to the right (Figs. '9, 12), swinging the pivot point N across operation, turns the in full lines in Fig. 1 to its normal position ing from the top so that the pivot point N,

. bean accelerating rate. The converse of the nut N, is moved from the position shown in Fig. 12 to the position shown in Fig. 10. All the parts thus occupy the same position as they did before the treadle 0 was depressed to place the mechanism described in operation. After the disc E has been removed and a new disc substituted, the treadle O is again depressed and the operation repeated.

In grinding spherical'surfaces, the abrasive wheel is generally arranged to commence atthe periphery of the work and finish at its centre, and as in grinding convex surfaces there is most work to be done at the periphery, it is desirable that the rate of turning about the secondary axis should is required for concave surfaces. 1'

For this purpose I may employ any con venient means, but I prefer, while using a weight to effect the turning, to use means for retarding its rate of descent, and such means may comprise a dashpot R which may have the form of an ordinary liquid door check attached to the column 0, the crank R, of

'such check being connected by a connecting rodR with a crank arm R, on the seconda axis shaft N (see Fig. 11), and either or both of the crank arms may be so set that the resistance of the dashpot to the turning of the shaft diminishes or increases throughv out the grinding operation.

As a further means of securing such ac- F celeration or deceleration, I may so set one or both of the cranks O O connecting the treadle to the weight'that the effect of the.

weight of the treadle upon the turning of the shaft changes suitably throughout the grinding operation. Furthermore, with the some object, I may so adjust or vary the weight N and resistance of the dashpot R, that, when b reason of there being much material to e removed the resistance to turning the work about the secondary axis is a maximum, the Wei ht N which may be varied by adding welghts N (Fi s. 8, 9?i is about sufli cient only to turn the Wor at the desired rate, and as'the operationproceeds and the resistance to turning diminishes, the rate of turning will automatically increase, but cannot exceed a rate predetermined by the setting or adjustment of the dashpot R. Such adjustment may be the .adjustment of. aby-pass 3 such 'as'is usual in a liquid door check.

When a freshblank E has been inserted in the chuck and'the Wvork is turned about the secondary axis I, it is desirable that, without being "hindered by the retardin device R, it should be free to be turne promptly into the position where the work is about to encounter the abrasive wheel, and

- at this point only the retarding device should commence its operation.

For this purpose I prefer to form the connecting rod R which connects the crank arms R R on the check It and the shaft N respectively, with a longitudinal slot R, engaging one of the cranks so as to permit backlash, and I provide a screw R or the like means for varying the length of such slot (Fig. 11), I

The machlne which has been described and is illustrated in-the drawings is adapted for grinding convex spherical surfaces, but it will be understood that, by withdrawing the Work and work spindle longitudinally 'to the other side of the secondary axis and grinding with the p the machine could e employed for grinding" eriphery of a disc wheel,

concave surfaces. Y

In order to set the machine for accurately grinding'spherical surfaces of any required radius of curvature, I may provide an adjustable gauge which may have the form of a bar S that can be adjustably mounted in the work spindle carriage H in a position parallel to the axis of the work,- spindle F. The end of the bar S may be set to make contact with the face of the abrasive wheel A, while for the purpose of measurement the bar S may be provided with a slider S and co-operating graduations S The bar S is adapted to beclamped by. means of the screw S in position in the slider S which may be set to abut against a fixed surface H,. on the work spindle carriage- H or otherwise suitably correthe wheel.

The guard may also have an o ening A below for the escape of surplus i uid and be rovided in its interior with a so water projected tangentially from the rotating wheel will not be atomized by splashi'ng thereon. 1

4 Having thus described. the nature of'the said invention and the best means I know ore A evelled or; curved in section that the of carrying the same'into practical effect, I

claim A grinding machine, com rising in combination a rotary grinding w eel, a ro-I tary work holding member, andmea'ns for automatically traversing the grinding wheel across the work during a. grinding operation by relative movement between said wheel and member about an axis intersecting the axisof rotation of the work holding memher, said means including means whereby.

. rate.

2. A grinding machine, comprising in combination a rotary grinding wheel, a rotary work holding member, means for traversing the grinding wheel across the work during augrinding operation by relative movement between said wheel and member about an axis intersecting the axis of rotation of the work holding member, and means for retarding such relative movement.

3. A grinding machine, comprising in combination a rotary grinding Wheel, a rotary work holding member, means for traversmg the grinding wheel across the work during a grinding operationbyrelative movement between said wheel and member about an axis intersecting the axis of rotation of the work holdin member, and

means for retarding such re ative movement comprising a fluid check device. I

A. A grinding machine, comprising in combination a rotary grinding wheel, a rotary work holding member, means for traversing the grinding wheel across the work during a grinding operation by relative movement between said wheel and member about an axis intersecting the axis of rotation of the work holding member, said means includin means for applying a"lim-' ited force tending to efi'ect such movement and means for limiting the rate of such movement, whereby the rate of such movement may vary inversely with the resistance to grinding but cannot exceed a predetermined rate, f

5. A grinding machine, comprising in combination a rotary grinding'wheel, a rotary work holding member, means for producing between said wheel and member a relative movement about an axis intersecting the axis of rotation of the workholding member, said means. including means for applying a definitely limited force to efiiect such movement, and a device for limiting the rate of such movement, adjustable to vary such rater 8. A grinding 'achine, comprising in combination a ro' ry work holding member,

a rotary grindin wheel having an annular grinding edge operable across the face of the work carried by the work holding memher, and mea s for producing between the work holdin member and wheel a relat ve movement a out an/ axis intersecting the axis ofrotation of the work holding memher under definitely limited force and at a rate which may be less than but cannot exseed a predetermined rate.

7.-"A grinding machine, comprising, in

antenna combination, a rotary grinding wheel having an annular grinding edge, a rotary work holding member, and means for causing a r'otative movement of said work holding member about an axis intersecting the axis of rotation of said work holding member at a-fixed angle thereto and at a point which, duringtbe grinding operation, is at a fixed distance both from the operative edge of producing between the work holding memher and wheel a relative movement about an axis intersecting the axis of rotation of said member, said means including means for applying a definitely limited force to effect such movement, and means for limiting such movement so as not to exceed a predetermined rate,

9. A grinding machine, comprising in combination a rotary grinding wheel, a rotary work holder, one of said members being mounted to turn about an axis intersecting the axis of rotation of the Work holder for causing a relative traversing movement between the work and the edge of the grinding wheel, and means for eiiecting such movement at a rate which increases throughout the grinding operation. g

10. A grinding machine, comprising in combination a rotary grinding wheel, a rotary work-holding member, means for producing between said wheel and member a relative approaching movement at a rapid rate until the work is about to reach the grinding wheel, and'then a relative movement about an axis intersecting the axis of rotation of the work-holdin member at a slower rate during the grinding operation.

11. A grinding machine, comprising in combination a rotary grinding wheel, a rotary work holding member, means for producing between said, wheel and member a relative movement about an axis at an angle to the axis of rotation of said member and at a rate varying automatically and inversely with the resistance between the work-ear-' a gravity member for producing between comprising in said wheel and member a relative movement about an axis at an angle to the axis of rotation of said member and at a rate varying automatically and inversely with the resistance between the work carried by said member and said grinding wheel, and means for preventing such relative movement exceeding a predetermined maximum rate.

13. A grinding machine, comprising in combination a rotary grinding wheel, a ro-- tary work holding member, and automatic means for producing between said wheel and member a relative movement about a given axis at a rate below a predetermined maxithen automatically at a slower rate during the grinding operation.

15. A grinding machine, comprising in combination a rotary grinding wheel, a rotary work holding member, and means for producing between said wheel and member a relative movement about an axis intersecting the axis of rotation of the Work holding member, first forward at a rapid rateuntil the work is about to reach the grinding wheel, then automatically at a slower rate during the grinding operation, then backward at a rapid rate.

16. A grinding machine, comprising in.

combination a rotary grinding wheel, a rotary work holding member, means for producing between said wheel and member a relative movement about an axis intersecting the axis of rotation of the work holding member, and retarding means arranged to come into operation when the work 1s about to reach the grinding wheel to limit the rate of such movement during the grinding operation.

17. A grinding machine, comprising in combination'a rotary grinding wheel, a rotary work holding member, and means for producing between said wheel and member a relative'movement about a secondary axis intersecting the axis of-rotation of the work holding member, said'means comprising a screw having its axis in line with said secondary' axis, a nut engaging said screw and means for moving one of said screw threaded members longitudinally relatively to the other to effect such movement.

18. A grinding machine, comprising in combination a rotary grinding wheel, a rotary work holding member, means for producing between said wheel and member a relative movement about an axis intersecting the axis of rotation of the work holding member, said means comprising coacting screw threaded members one of which is movable longitudinally relatively to the other to efl'ect such movement, means for holding one of said screw threaded members against rotation during said relative longi- .tudinal movement, and means operating to render said holding means inoperative after a grinding operation. I

19. A grinding machine, comprising in combination a rotary grinding Wheel, a rotary work holding member, means for producing between said Wheel and member a relative forward movement about' an axis intersecting the axis of rotation of the work holding member, said means comprising 00- acting screw threaded members one of which is movable longitudinally relatively to the other to effect suchforward movement, means for holding one of said screwv threaded members against rotation during said relative longitudinal movement, means operatmgto render said holding means inoperative after a grinding operation, and

-means operating to efl'ect a relative backward movement between the grinding wheel and the work holding member when said holding means has been rendered inoperative.

20. A grinding machine, comprising in combination a rotary grinding wheel, a notary work holding member, means for pro ducing-between said Wheel and member a relative movement about an axis intersecting the axis of rotation of the work holding member, said means comprisin coacting screw threaded members one of which is movable longitudinally relatively to the other to efiect such movement, means for holding one of said screw threaded'members against rotation during said relativelongitudinal movement, means operating to render said holding means inoperative after a grinding operation, and means for returning said movable "screw threaded member to starting positionand rendering said holding means operative.

21. A grinding machine, comprising in :combination'a rotary grinding wheel, a rotary work holding member, means for promovable screw threaded member to startingposition and said toggle to holding position.

22. A grinding machine, comprising in combination a rotary grinding wheel, a ro-' tary work holding member,-means for producing between said wheeland member a relative movement about, an axis intersecting the axis of rotation of the work holding member, said means comprising coacting screw threaded members one of which is movable longitudinally relatively to the other to efi'ect such movement, means for holding one of said screw threaded members against 4 rotation during said relative longitudinal fmovable longitudinally relatively to the other to efl'ect such movement, and a wei ht for moving said longitudinally mova le member.

24. A grinding machine, comprising in combination a rotary grindingiwheel, a rotary work holding member, and means for producing between said wheel and member a relative movement about-an axis intersect-'- ing the axis of rotation of the wbrk holdingmember, said means comprising a screw threaded shaft, a nut engaging the screw thread of said shaft and adapted by lon= gitudinal movement to turn the shaft, a

weight adapted to give the nut its shaftv turning movement, means for holding the nut against rotation while making its shaft turning movement, means operating to render said holding means inoperative after a grinding operation to permit the shaft to be turned backward, and means for lifting the weight and turning the nut to starting position and rendering said holdingmeans operative. a .1

25. A grinding -mach1ne, comprising in combination a'rotary grinding wheel, a ro-.

tary work holding member, means for turna ing the work holding member about an axis intersecting the axis of rotation of the work holding member to move the work past the;-

operative face of the grinding wheel, said means comprising coacting screw threaded members one of which is movable longi- 'tation during such relative longitudinal tudinallyrelatively! to the other to efiect such movement, means for holding one of said screw threaded members against romovement, meanstoperating to render said holding means inoperative after a grinding operation,v and means operating to return antenna a the work holding member to its normal position of rest when said holding means has been rendered inoperative.

26. A grinding machine, comprising, in combination, a rotary work holding memher, a rotary grinding wheel having an annular grinding edge operable across the face of the work carriedby said work holding member, and means for producing between the work holding member and wheel a relative movement about an axis intersecting the axis of rotation of the work holding member at a fixed angle and at a point which, during the grinding operation, is at a fixed distance both from the operative edge of the wheel and from the work holding member.

21A grinding machine, comprising, in combination, a rotary work holding member, a rotary grinding whee-1 having an annular grinding edge operable across the face of the work carried by said work-holding member, means for producing between the. work holding member and the wheel a relative movement about an axis intersecting the axis of rotation of the wbrk holding member at a fixed angle and at a point which, during the grinding operation, is at a fixed distance from the work holding member, and means for adjusting the grin d-' ing wheel axially to take up for wear on its I grinding edge so as to retain its operative edge at a fixed distance from said intersection.

28. A grinding machine, comprising, in combination a rotary grinding wheel having an annular grinding edge, a rotary work holding c member, and supporting means for said grinding wheel. and the work holding member permitting =relative rotative movement between the same about-a sec-- ondary axis intersecting the axis of the work holder, said supporting means including means whereby said grinding wheel may be moved longitudinally of its axis and means whereby said' work holding member may be moved longitudinally of its axisfto vary the distance between the operative point of said wheel and the secondary axis.

29. A-grinding machine, comprising, in 2 combination, a Work holder for rotating the work about, an axis passing throughthe surface to be ground, a grinding wheel positioned to contact with the work during a grinding operation, automatic means for causing a relative separating movement bev tween the work and the grinding wheel on the completion of a grinding operation, and means automatically brought into opera tion by said separating movement tor cans-l ing the rotation of the work to cease.

-30. A grinding machine, comprising, in combination, a work holder. for {rotating the work about an axis passing through the surface to be ground, a grinding wheel,

point of means for causing between the inding wheel and the work a relative bodil movement'adapted, to traverse the grinding wheel over the face of the work, and means automatically actuated by said relative bodily movement for causing a separation of the work and wheel and for stopping the rotation of the work on the completion of a grinding operation.

31. A grinding machine, comprising in combinatiolra grinding wheel, a rotary work holding member, means for turning the work holding member about an axis intersecting the axis of rotation of the work holding member to move the :work past the edge of the grinding wheel and for transferringsaid member to a. position of rest after a grinding operation is completed,

' and means for causing the rotation of the work holding 'member to cease when it is returned to its position of rest and to be, resumed when said member is moved to begin a new grinding operation.

combination a rotary grinding Wheel, a rotary work holding device, and means for producing between said wheel and device a relative movement about a secondary axis intersecting the axis of rotation of said device, said device comprising a work spindle, a chuck thereon operated by movement longitudinally of the spindle, and

means determining the position of the chuck with respect to the secondaryaxis independently of the position of the work spindle,

' whereby the work is ground to a uniform thicknes regardless of its diameter.

i 33. A grinding machine, comprisin in combination a rotary grinding whee a rotary work holding device, and means for producing between said wheel and device a a relative movement about a secondary axis intersecting the axis ofrotation of said, device, said device comprising a work spindle, a chuckv thereon operated by movement longitudinally of thespindle, means deter-' mining the position of the chuck with respect to the secondary axis independently of the position of the spindle whereby the work is ground to a. uniform thickness regardless of its diameter, and',means for moving said chuck longitudinally to open the same.

'34; A grinding. machine, comprisin in combination a rotary grinding whee a rotary work-holding device, and means for producing between said wheel and device a relative movement about a secondary axis\ intersecting the axis of rotation of said device, said device comprising a work.

spindle support, a work spindle having a -limited axial movement in "said support, a chuck upon said spindle adjustable axially thereof, and an abutment cooperatingiwith-said chuck to determine lts posibetween-said wheel an ,tion with said releasing meansh tion a with respect to the secondary axis independently of the position of the spindle.

' 35. A machine'for grinding spherically curved surfaces, comprising in combination a rotary grindingwheel, a rotary work holding member, means for, traversing the surface of the work across the operative surface of the grindin wheel'by producing said member during a grinding operation a relative movement about a secondar axis intersecting the axis of the work ho ding "member, and automatic means for causing a sepa'rating movement between the grinding wheel and-the work in a direction different from said first-' so mentioned movement upon completion of a grinding operation. I

36. A grinding machine, comprisin in combination a rotary grinding whee a rotary work holdin member, means for 86 moving the work ho der about an axis intersectmg the axis of rotation of the work holder frond a position of rest across the,

grinding wheel during a grinding operation, and'automatic means for. withdrawin to p the work holder from the grinding whee and returning it to such position of rest after the completion of a grinding operation.. 4

37. A grinding machine, comprisin in 05- combination a rotary grinding whee a wheel,'means for causing between the worn 1 0 and wheel a relative turning movement.-

about an axis intersecting the axis of rotation of the .work, the grinding wheel vbeing so formed and arranged that the middle.

point of thefline of contact between the 1 5 I wheel and the work is moved across the face of the 'work along a radial line 10min the periphery and axis'of the work by sai turning movement, and means-for ,automatically separating the wheel 31nd work when the middle point of the line. of contact reaches one end of said radial line.

39, A machine for grinding "spherically,

curved surfaces, comprising meansfor rotating the work about an axis passing through i the surface to beground, a rotary grinding wheel, means for causing between the wheel 7 and the work a relative turning movement H about an' axis intersectingv the axis of the work, the grinding wheel being so formed I I rare and arranged that the middle point of the line of contact between the wheel and the -holder and the wheel a relative turning movement about a secondary axis intersecting the axis. of rotation of the work, the grinding wheel being. so formed and ar ranged that the line of contact between the wheel and the work is moved by said turning movement across the face of the work, means for retaining the wheel and the work holder at fixed distances from the secondary axis during the grinding operation, and automatic means for stopping said turning movement on completion of a grinding operation.

41. A machine for grinding spherically curved surfaces comprising a work holder rotary about an axis passing through the surface to be ground, a rotary grinding wheel, means for causing between'said wheel and said work holder a relative turning movement about a secondary axis intersect- .ing the axis of the work holder, the grinding wheel bein so formed and arranged that the line of contact between the wheel and the work is moved by said turning movement across the face of the work, means for retaining said wheel and said work holder at fixed distances from the secondary axis during a grinding operation, and automatic means for separating the wheel and work on completion of a grinding operation.

42. A machine for grinding spherically curved surfaces, comprising a work holder having a surface adapted to engage and position the rear face of the work, means for rotating said work holder about an axis passing through the front face of the work, a rotary grinding wheel, means for causing between said wheel and said work holder a relative turning movement about an axis intersecting the axis of the work holder,

the grinding wheel being so formed and arranged that the middle point of its-line) of contact with.the work is moved from the edge to the axis of the work by said i turning movement, means for retaining the positioning surface qf the work holder at a fixed distance from the secondary axis dur- 'ing such turning, and automatic means for stopping said turning movement when the middle oint of the line of contact between the wor and the wheel reaches the axis of the work.

s 43. A grinding machine, comprising in combination a rotarygrinding wheel, a rotar'y work holder, means for causin be-.

tween said wheel and said work holder a relative turning movement about an axis intersecting the axis of the work holder,

through an arc of predetermined length.

and means for varying the rate of said movement by variable increments without varying the length of said are. 5

44:. grinding machine, comprising in combination a rotary grinding wheel, a rotary work holding member,'means for producing between said wheel and member a relative movement about an axis intersecting the axis of rotation of the work holding member, first, at a rapid rate, then, auto matically at a slower rate, and imgansfor varying the are through which the move ment is efiected atthe slower rate.

d5. A grinding machine, comprising in combination a rotary grinding wheel, a r0 tary work holder, turning means for causing a movement of said work holder about an axis intersecting the axis of rotation of the work holder, means arranged to set.

'said turning means in operation, driving means for rotating the work holder, andsec ting the axis of the work spindle, and means cooperating with said chuck to determine the position of the work relatively to the secondary axis independently of the relative longitudinal position of said spindle andchuc'k and comprising an abutment having a predetermined positional relation to the secondary axis 7 ln testimony whereof I have. signed my' name to this specification in the presence of two subscribing, witnesses.

- WM. TAYLUR.

Witnesses:

Y. E. ltlnnson, Ensm M. BENT.

llU 

